A drug delivery device is a medical device for delivering drug agents. A charge of a drug agent to be delivered usually comes in a cartridge, and the drug delivery device here may therefore be configured to accommodate at least two cartridges. Each cartridge forms a separate reservoir of the drug agent. When the drug delivery device only has a single injection needle to deliver the drug agents, a valve construction may be necessary to control the flow of the drug agents from their respective cartridges to the injection needle.
There are various medical devices for delivering at least two drug agents from separate reservoirs. Such drug agents may comprise a first and a second medicament. Such a medical device includes a dose setting mechanism for delivering the drug agent(s) automatically or manually by the user.